If the famous cryptid is real, this hunt ought to find it—but if not, scientists will still gain valuable ecological data.

A group of scientists plans to find out once and for all if Scotland's most famous “resident,” the Loch Ness Monster, is or ever was hiding in the deep by sequencing as many DNA fragments as they can find in the lake's murky waters.

Since April 2018, an international research team led by University of Otago geneticist Neil Gemmell has collected water samples from the iconic freshwater lake. In June, Gemmell's team will begin extracting DNA from the samples, hunting in part for Nessie's genetic fingerprint.

The team expects to announce their findings by January 2019. In the meantime, the project will shine a bright spotlight on environmental DNA, or eDNA for short—a relatively new field of study that's giving scientists unprecedented insights.

Wondering what the Loch Ness project is all about? We've got you covered.

What is environmental DNA?

As organisms go about their daily lives, they leave bits and pieces of themselves behind: skin, poop, eggs, sperm, you name it. This bio-schmutz contains samples of the organisms' DNA, which then get mixed into the surrounding water and dirt. That means a single vial of soil or water can act as an accidental genetic library. Scientists can isolate and decode this eDNA and compare it against a database of known DNA sequences to identify the creatures that left it behind.

Recently, the reference database has exploded in size as more sequences pile up and the cost of sequencing continues to plummet. The number of DNA bases in Genbank, a major DNA database run by the U.S. National Institutes of Health, has doubled every 18 months since 1982. It now holds more than 260 trillion base pairs of DNA spread out across more than 200 million sequences.

How does environmental DNA help science?

Environmental DNA is so powerful because researchers can get a genetic snapshot for an entire ecosystem in one fell swoop.

“Imagine being able to take soil or water samples from an ecosystem and catalogue every species living in that ecosystem,” Helen Taylor, a University of Otago researcher who works with Gemmell, said in a 2017 blog post about eDNA. “No more invasive sampling or taking whole organisms back to the lab to ID them under a microscope.”

And currently, a National Geographic Society team is trying to extract eDNA from soil sampled at the South Pacific island of Nikumaroro to see if a suspected gravesite there belonged to lost aviator Amelia Earhart.

What does this have to do with the Loch Ness Monster?

The Loch Ness monster, or Nessie, is rumored to live in Loch Ness, a deep freshwater lake in northern Scotland carved by glaciers more than 10,000 years ago. Tall tales of sightings have persisted for decades, but scientists consider the classic image of Nessie—a long-necked reptilian creature—to be an impossibility and a hoax.

Some cryptozoologists have argued that Nessie is a plesiosaur, a type of long-necked marine reptile that lived during the age of dinosaurs. Fossil evidence strongly suggests that, like nonavian dinosaurs, plesiosaurs went extinct no later than 66 million years ago.

Even if some plesiosaurs have survived to the present, it'd be difficult for them to live in the loch. Ecological studies suggest that Loch Ness doesn't have enough fish to sustainably feed a breeding population of plesiosaurs, which could weigh upwards of 2,000 pounds each.

As an alternative, some theorists suggest that Nessie's witnesses have actually spotted a wayward sturgeon or an introduced Wels catfish. However, neither fish has been captured in the loch yet.

“There is no evidence of the wels in Loch Ness, any more than there is any evidence of my favorite [candidate], sturgeon,” Loch Ness Project head Adrian Shine wrote in an email to The Skeptic. “Both theories originated as our attention focused more and more upon fish candidates among the reducing possibilities of any real unusual creatures being the cause of sightings.”

So is the environmental DNA project useless?

Not at all. Gemmell's research should result in a genetic profile for the entire Loch Ness ecosystem—a handy thing to have no matter what they find. Invasive species of salmon are entering Loch Ness and threatening native species, for instance, and the eDNA profile should help monitor them.

Publicity is also no small thing, especially for a rapidly developing scientific field. “I was skeptical about my lab head joining the hunt for the Loch Ness monster,” Taylor wrote in 2017, “until I realized it was an excellent way to promote the amazing possibilities of environmental DNA.”